Di(lower alkyl)-mono(alpha-phenyl-beta-carbalkoxy-vinyl) phosphate esters



nited States ate DI(LOWER ALKYL)- MONO(a-PHENYL-fi-CAR- BALKOXY-VINYL)PHOSPHATE ESTERS Walter Lorenz, Wuppertal-Elberfeld, Germany, assignorto Farbenfabriken Bayer Aktiengesellschaft, Leverkusen, Germany, acorporation of Germany as Drawing. Application July 16,1957 Serial No.672,122

This invention relates to and has as its objects new and usefulphosphoric acid esters as well as their preparation. It has been foundthat phosphoric acid esters of the general formula OOR wherein R and Rdenote an alkyl, aryl or aralkyl radical, distinguish themselves by anexcellent insecticidal action. Besides a good action on plant lice theyhave a very good action on larvae of flies or gnats.

The production of these compounds may be carried out by known methods,for example by conversion of sodium aroyl esters with dialkyl-phosphoricacid chlorides.

Cl Aryl-O-JJH-C OOR The last mentioned process is described e.g. byArbuzov in J. Chem. (Russ) 20 (82) 1468-1477, see also Chem. Abstracts42, 4523-4524.

Compared with the compound known from Bios Final Report No. 714 in whichinstead of an aryl radical there is a methyl group (which is derivedfrom acetoacetic ester), the aryl compounds have a markedly lowinhalation toxicity which is of decisive importance for the practicalapplication of phosphoric acid esters which are known to be poisonous.

Moreover, the phosphoric acid esters according to the invention areintended to be applied against the boll weevil (a cotton pest) therebyattaining a persistent protection the efiect of which is for examplethree times that of the acetoacetic derivative.

The phosphoric acid esters according to the invention may be applied inthe usual form, i.e. in admixture with a liquid or solid diluentincluding, if so desired, an emulsifier and other additives. Thecompounds according to of specifically illustrating the utility of theinventive compounds.

.The diethyl phosphoric acid ester of the enol form of the benzoyl esteracid ethyl ester was sprayed in the form of an aqueous emulsion by useof the same amount of benzyl-hydroxy-diphenyl (0.1%) polyglycol ether oncotton plants at a concentration of 0.1% active ingredient. The mixtureof emulsifier and active ingredient was preprepared and then dilutedwith water to a 0.1% emulsion. During the tests, the treated plants werekept in cages in the open air and infested with -125 plant lice and redspiders respectively, and with a smaller number of boll weevils. Themortality of plant lice and red spiders was assayed after three days andof boll weevils after five days. The results are listed in the followingtable. For comparison, the test was also carried out with the diethylphosphoric acid ester of the enol form of acetoacetic acid ethyl ester.

mortality in percentages boll weevil red spider cotton plant licediethyl phosphoric acid ester of the enol form of the aceto aceticester;

diethyl phosphoric acid ester of the entol form of the benzoyl acetic eser The following example may illustrate this invention, without limitingit, however, thereto.

Example H-0 0 O 02H:

CH-O 0 0 C211;

OOH:

Using the equivalent molecular amounts of the methyl Patented July 7,1959,

ester of a-chlorobenzoyl-aeetic acid and trimethyl phosphite there isobtained the following ester H-C O O CH:

It has to be understood, however, that also other suitable substitutedbenzoyl or other aroyl acetic acid derivatives may successfully be used,yielding also valuable novel esters with remarkable insecticidalproperties.

This application is a continuation-in-part of my copending applicationSerial No. 515,210, filed June 13, 1955, now abandoned.

4 I claim: Phosphoric acid esters of the general formula Ii/Phenyl-(|'|J-0-P in OR C O 0 R1 wherein R and R stand for a lower alkylradical.

Naturwissenschaften, vol. 42, p. 415, 1955. Chem. Abstracts, vol. 42,pp. 4523-4524.

